10 p.m. CST Friday, Dec. 15, 2006
Mission Control Center, Houston, Texas
STS-116 MCC Status Report #13
The crews of Space Shuttle Discovery and the International Space Station tried again to refold an accordion-like solar array with help from engineers and flight controllers on the ground, but none of the techniques succeeded in clearing the jam.
The final attempt of the day came at 8:04 p.m. CST when Expedition 14 Flight Engineer Sunita Williams deployed the P6 solar array blanket slightly and then retracted it the same distance. This left 14 of the array’s 31 bays in their storage box, the same condition in which they started the day.
After the deployment and retraction technique made no significant progress in clearing the jam, the team briefed the crew on an inspection task that is being planned for use at the end of the mission’s third spacewalk. The task would be added only if the rest of the electrical rewiring activities planned for the excursion go smoothly. Mission managers have not yet decided whether a fourth spacewalk will be attempted, but the inspection task on the third spacewalk could provide information valuable to those making the decision.
Earlier in the day, flight controllers “wiggled” the solar arrays using the beta gimbal assembly, a rotating mechanism on the truss, and the crew worked out vigorously on an a resistive exercise device. Both techniques were attempts to jostle the guide wires and stainless steel grommets that are believed to be the cause of the stalled retraction.
The third spacewalk is scheduled to begin at 1:37 p.m. CST Saturday. During the excursion, Mission Specialist Bob Curbeam and Williams will finish rewiring the station’s power system, stow three Service Module Debris Panel bundles, install an adjustable grapple bar and, if time permits, troubleshoot the problem with the stuck array. The spacewalk will be Williams’ first.
In addition to their troubleshooting activites, the crew shared its experiences in space with both U.S. and European news media during a joint press conference today, and the two European Space Agency astronauts, Christer Fuglesang of Sweden and Thomas Reiter of Germany, participated in a VIP call with Swedish dignitaries.
STS-116 Commander Mark Polansky, Pilot Bill Oefelein, Mission Specialists Nicholas Patrick, Joan Higginbotham, Curbeam, Reiter and Fuglesang also continued to transfer food, supplies and equipment with the help of Expedition 14 Commander Mike Lopez-Alegria and Flight Engineers Mikhail Tyurin and Williams. The spacefarers also enjoyed some off-duty time together.
Meanwhile, the new Port 4 solar arrays continued to rotate and track the sun, generating power for the station. Flight controllers completed re-powering station systems using the updated electrical grid and power from the new solar arrays delivered in September.
To prepare for the spacewalk, Curbeam and Williams will “camp out” in the Quest airlock starting at 10:57 p.m. Spending the night at a reduced atmospheric pressure of 10.2 psi will purge their bloodstreams of nitrogen bubbles to protect against “the bends.” The rest of the crewmembers begin their sleep period at 12:47 a.m. Saturday.
The next STS-116 status report will be issued Saturday morning or earlier if events warrant.